Vitamin B₁₂ deficiency: A case report of ongoing cutaneous hyperpigmentation

We describe an interesting case of a man with recurrent cutaneous and hematologic manifestations of vitamin B₁₂ deficiency. In this deficiency, the skin, central nervous system, blood, and bloodforming tissues are commonly involved. We describe an overview of vitamin B₁₂ deficiency and the successful treatment of a patient's ongoing cutaneous hyperpigmentation.